A Combined
Experimental and Theoretical Study of the Ti<sub>2</sub> + N<sub>2</sub>O ReactionMarzoukA.BolvinH.ReinhardtP.ManceronL.PerchardJ. P.TremblayB.AlikhaniM. E.2014The reactivity of diatomic titanium
with nitrous oxide has been studied in solid neon. Two molecules with
the same Ti<sub>2</sub>–N<sub>2</sub>O stoichiometry are identified
from concentration, temperature, and irradiation effects. The more
stable one is characterized by five fundamental vibrational transitions
located below 1000 cm<sup>–1</sup>, the high frequency one
at 946 cm<sup>–1</sup> corresponding to a pure TiO stretching
mode. Its structure, a rhombus OTiNTiN with the extra O atom fixed
on one Ti, is confirmed by quantum chemical calculations, at the CCSD­(T)
level, which predict a <i>C<sub>s</sub></i> structure in
the singlet state with a Ti–O bond length close to 1.66 Å,
two nonequivalent Ti–N distances close to 1.94 and 1.75 Å,
and a OTiTi angle of 119.2°. The second Ti<sub>2</sub>–N<sub>2</sub>O molecule, only observed after annealing, is easily converted
into the first one upon irradiation above 12 000 cm<sup>–1</sup> and its kinetics of photoconversion allows vibrational transitions
to be identified. The strongest one located at 2123.4 cm<sup>–1</sup> characterizes an N–N stretching mode. Corresponding ab initio
calculations complete this picture with details on the electronic
structure and allow us to identify a most adequate density functional
to describe the spectroscopic properties of the studied species in
a simpler broken-symmetry open-shell DFT context. The theoretical
results predict the existence of a metastable product OTi<sub>2</sub>N<sub>2</sub> and correctly account for the observed spectra of the
various isotopic varieties.